drm/i915/tgl/dsi: Set latency PCS_DW1 for tgl

Latency programming remains same as that of ICL and
setting latency otimization for PCS_DW1 lanes is same as
that of EHL, hence extending it to TGL.

Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190730073648.5157-3-vandita.kulkarni@intel.com